The subject matter disclosed herein relates to a fuel-air premixer. Specifically, the present disclosure relates to an airfoil-shaped centerbody for a fuel-air premixer in a gas turbine combustor.
Gas turbine and engine systems provide power for a variety of applications, such as oil and gas processing systems, commercial and industrial buildings, and vehicles. The gas turbine and engine systems may combust a mixture of fuel and air in a combustion system (e.g., chamber) to generate power. The combusted fuel and compressed air generate hot combustion gases, which, in turn, drive blades of a turbine to produce rotative power, for example. Accordingly, the combustion system of a gas turbine may include a mixer that produces a homogenous mixture of fuel and air to be fed into the combustion system. In some cases, the mixer may not produce a substantially homogenous mixture because of a limited amount of time that the fuel and air may spend in the mixer and because of undesirable effects, such as recirculation pockets. Therefore, gas turbine and engine systems may include a premixer designed to begin mixing the fuel and air before such components enter the mixer.
Exhaust gas produced by the gas turbine engine may include certain byproducts, such as nitrogen oxides (NOx, including NO and NO2), sulfur oxides (SOx), carbon oxides (COx), and unburned hydrocarbons. The type of exhaust gases emitted, as well as the amount of exhaust gases emitted, may depend at least in part on a composition of the fuel-air mixture. Many industries and jurisdictions (e.g., coal-burning plants, federal and state governments, etc.) may have regulations and restrictions specifying the types and amounts of exhaust gases that a given system is permitted to emit. To achieve emissions levels specified by some jurisdictions, it may be desirable to enhance a mixing quality of the air-fuel mixture fed to a combustion chamber of the gas turbine and engine system. Accordingly, it is now recognized that an improved design of the premixer may be desirable.